‘Christianity...does something different. It makes frankly impossible demands. Instead of asking for specific actions, it offers general but lunatic principles. It thinks you should give your possession away, refuse to defend yourself, love strangers as much as your family, behave as if there’s no tomorrow. These principles do not amount to a sustainable programme. They deliberately ignore the question of how they could possibly be maintained. They ask you to manifest in your ordinary life a drastically uncalculating, unprotected generosity. And that’s not all. Christianity also makes what you mean all –important. You could pauperise yourself, get slapped silly without fighting back, care for lepers and laugh all day long in the face of the futures markets, and it still wouldn’t count, if you did it for the wrong reasons. Not only is Christianity insanely perfectionist in its few positive recommendations, it’s also insanely perfectionist about motive. It won’t accept generosity performed for the sake of self-interest as generosity. It says that unless altruism is altruism all the way down, it doesn’t count as altruism at all.
So far, thrillingly impractical. But now notice the consequence of having an ideal of behaviour not sized for human lives: everyone fails. Really everyone. No-one only means well, no one means well all of the time. Looked at from this perspective, human beings all exhibit different varieties of fuck–up. And suddenly in its utter lack of realism Christianity becomes very realistic indeed, intelligently resigned to our vast array of imperfections, and much more interested in what we can do to live with them than it laws designed to keep them segregated.’
Francis Spufford, Unapologetic, p.45.